1. Field of the Invention
The present invention relates to a working machine such as a chip mounter designed to mount an electronic circuit chip onto a printed wiring board. In particular, the invention relates to an identifying unit and a pressure apparatus utilized in the working machine.
2. Description of the Prior Art
A chip mounter is well known as disclosed in Japanese Patent Application Publication No. 2004-55705, for example. The chip mounter includes a working head opposed to the surface of a work stage. A movable member is designed to move toward and away from the surface of the work stage in the chip mounter. The movable member is supported on a guide for relative movement. A load cell is fixed to the movable member. The working head is detachably coupled to the load cell. When the working head is urged against a printed circuit board on the work stage, the applied load is measured at the load cell.
Various working heads are prepared for the chip mounter depending on the purposes. Control parameters may be selected for the individual working heads in the chip mounter. The control parameters are employed in controlling the position of the movable member and the thrust of the movable member. Bar codes are heretofore employed to identify the working head in setting the control parameters, for example. When the bar code is erroneously detected in the chip mounter, the control parameters cannot correctly be set for the working head on the movable member in the chip mounter.